Politics and the English Language is a pretty seductive essay, but on deep examination, it doesn't really make its own case beyond some sentimental appeals and rhetorical flourishes. In particular, its thesis seems to be language has "declined", but never cites any older uses of language save a line of the Bible, which he contrasts with bureaucrat-ese and journalistic writing; he makes rough insinuations that the language can somehow affect (or even effect) thought but doesn't bother justifying how or why beyond simple rhetorical devices ("But if thought corrupts language, language can also corrupt thought [citation needed]"); he insists on a few rules to keep your language sharp, but these rules are ridiculously broad and, indeed, so hard to follow while producing clear writing that he breaks most of them himself within the first two paragraphs: http://languagelog.ldc.upenn.edu/nll/?p=992

The idea that you can adopt simple rules and somehow come up with speech that's not amenable to deception or fluffery is appealing for obvious reasons, but that's just not how language works: you can follow Orwell's rules to the letter, better than he does, and include just as much deceptive fluff; or you can ignore his rules and write forceful, interesting prose. (Orwell himself does!)

A rough analogue in the programming field would be the idea that you can "enforce" good code by nothing more than enforcing style guidelines. The idea that you can prevent lies in politics by banning the passive voice is roughly as silly as the idea that you can prevent bugs in code by banning tab characters.